Place meat, soy sauce, garlic, ginger, 2 teaspoons vegetable oil, and sesame oil in a large bowl.,Mix well, cover and refrigerate for at least 1 hour.,______,Heat remaining oil in a large skillet over high heat.,Add meat and stir-fry until tender, about 8 minutes.,Add vegetables and continue cooking until onions and peppers are tender-crisp.,Mix cornstarch and water and add to the reserved marinade.,Pour marinade mixture over meat and cook 5 minutes more.